v3.26.1
Derivatives and Hedge Accounting Activities (Schedule of Offsetting Assets) (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] $ 894 $ 741
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 94 65
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 800 676
Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 445 464
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 45 16
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 400 448
Commodity Contract | Over-the-counter    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 789 464
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 34 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 755 460
Commodity Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 406 239
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 34 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 372 235
Commodity Contract | Exchange    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 52 48
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 49 48
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 3 0
Commodity Contract | Exchange | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 3 0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 0 0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 3 0
Interest Rate Contract | Over-the-counter    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 51 201
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 9 5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 42 196
Interest Rate Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 34 197
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 9 4
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 25 193
Foreign Currency Exchange Rate Contract | Over-the-counter    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 2 28
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 2 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts 0 20
Foreign Currency Exchange Rate Contract | Over-the-counter | Virginia Electric and Power Company    
Offsetting Assets [Line Items]    
Gross Assets Presented in the Consolidated Balance Sheet [1] 2 28
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments 2 8
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received 0 0
Net Amounts $ 0 $ 20
[1] Excludes derivative assets of $285 million and $217 million at Dominion Energy and $10 million and $18 million at Virginia Power at June 30, 2026 and December 31, 2025, respectively, which are not subject to master netting or other similar arrangements.